Yamaha 300 HP not full going down

[HalcyonDays]

New to me 2018 300 HP Yamaha outboards do not go down all the way. It appears lower hydraulic pistons do not retract. The local service department says I need to add grease to the outer surface. Once this is done they will retract. Just doesn't seem right. My older Yamaha 250 never had this problem. Seems grease needs to happen every other time we go out. Is there a solution for this?

 

[seasick]

I am not convinced thatgrease will make a difference. In fact, you should not put a lot of grease on those rods with the exception of a little bit on the end. Of course if the piston rods are corroded, they could be stuck but that would be obvious when examining the shafts.
My first guess would be low oil but why both motors would act up at the same time is puzzling. Either way, I suggest you top off the reservoir.
I have to ask, are the tilt stops fully retracted?
Does you motor and have an option to set trim limits? I have that on myotherboat that has Mercs. If you have such an option, the tilt/trim motor will stop running when the limit is reached. If your trim motor continues to run, it is not a trim limit config issue.

You can raise a motor, up put the tilt stop in place, lower the motor onto the stop and while pressing the down button, tap the trim rods with a hammer. If stuck that should move them.
All in all, low fluid with air is my guess

 

[Coastboater]

Is the motor support bracket down?

 

[glacierbaze]

"Seems grease needs to happen every other time we go out."

Does it happen every time, or occasionally? My first thought was also trim limit sender. Put them down as far as they will go, and then loosen the manual pressure release screw on the side of the bracket, and see if they go further.

 

[HalcyonDays]

The two rods shown in the photos are the issue, one photo with boat in water second photo boat out of water. It doesn't happen every time out but once it does it they will not retract unless grease is added. The motors are five years old, first three years spent in fresh water, last two in saltwater. Never happened in fresh water, only started happening second year in the salt water. It happens to both motors not necessarily at same time. The motors go down fine until they hit the rods then stop. Normally the motors would go down until they it the rods then go down a little slower. My old boat with 2005 Yamaha 250 worked the same way except in the 18 years I owned the boat there was never a problem. The 2018 motors seen to sit lower one the transom of the Grady 307 than the 2005 motor did on my Grady 258.

 

[HalcyonDays]

Side note I am trying to remove ski pylon. Does anyone have any tricks?

 

[SkunkBoat]

So the trim motors are working? They raise the trim?
Does trim work up & down while the motor is down in the running position?
The problem is only when going from Tilted out of the water to lowering to contact trim rods?

Normally, The weight of the motor lowers the trim rods when the trim down is pushed.
That adding grese to the ends of the rods would make it work would imply that there is friction at the contact point.
Maybe sanding the contact point would help?

 

[seasick]

You need to fill the oil and bleed the system. There are instructions in the service manual but the process is simple. Raise the motor, deploy the tilt stop for safety sake, remove the tank filler cap and fill up the tank till it overflows ( use ATF transmission fluid. Get the original AFT, not the transmission fluid that mentions specific automobile manufacturers).
To bleed, raise the motor and take off the safety stop lever. Lower the motor as far as it will go. Raise the motor and repeat the fill operation. Repeat the full up and full down operation. You may need to repeat the operation several times. You can tell by the sound of the pump when there are air pockets in the lift pistons. Letting the system sit for a few minutes between refilling and cycling may help get the air out.
As to greasing. Excess grease can cause problems. At the most, a light application of water proof grease rubbed onto the shafts, followed by a wiping off of all but a thin coating of grease. Using paper towels or cloths that shed liny can lead to premature seal failure..

 

[HalcyonDays]

It would seem the weight of motors would push trim rods in and allow motors to fully go down. Many times they do not. The boat is new to me, I powered the boat from Mass to Maine. Motors worked fine. Starboard motor made strange noise going down when I first started out(but went all the way down) Port motor worked fine. Once in Maine, we docked boat lifted motors went home for night. Next day went down to use boat and Port motor would not fully go down starboard motor worked fine. Kept trying and eventually both starboard and port motor would not fully go down. Had boat pulled for season and mechanic said by adding grease (shown in second photo) motors worked fine. I went to boat yard and removed a lot of barnacles from motor brackets. Previous owner said they were having issues this season, it happened more than once. They were told to add grease also. I am curious if anyone else has had this issue? Like I said have owned Yamahas for twenty years and have never heard of this kind of issue, the grease thing just seemed strange to me. Motors have less than 150 hours on them, three years in fresh water, two years in salt water. In Maine, I typically do not get a lot of barnacle build up, maybe in Manchester, Mass. this is more of an issue.

 

[SkunkBoat]

Does this only happen when lowering from full up TILT or do you also have problems when trying to make trim adjustments while running?

I go back to the fact that adding a dab of grease to the TOP of the rod makes it work. That implies the Tilt and Trim pumps are working(I would still check fluid)
I believe the rods make contact on a replaceable bolt on the swivel bracket. Look closely at that contact point.
I'm not sure if that bolt is or isn't an adjustment of the contact point of the trim???

Unusual that its both motors, same intermittent problem. Only thing in common is the switch on the binnacle.
...but sometimes it just one motor....
Have you experienced the problem from both the binnacle(helm control) and at the switch on the motor?

It could also be somewhat effected by binding where the motor pivots in the bracket. There are grease fittings there and bushings. Is there a lot of creaking and groaning as the motors descend?

If the boat is out of water, troubleshooting will be easier. Remove the grease from the rods and contact point(in hopes of reproducing the problem). You can test from both the helm and the engines and observe as it contacts the trim rod.

If you can get it to fail, STOP! Is the trim motor running? Push down on the motor..does it go down?....Lift the weight of the motor and push the rods down.... if they can't move, turn the Manual Release screw and see if the rods can go down.
Obviously, its hard to describe everything to try but maybe you catch my drift?

 

[Legend]

I have 2017 4.2L f250s. Both trim units were replaced after one year under warranty - a year later one on the engine would only tilt down to the top of the trim pistons. The Dealer to told me to use the engines to force the engines down a a measure to keep boating for the week. He said it is a known Yamaha issue and it is a relatively easy fix. If I recall there are a couple of internal bolts that need to be replaced. Before they knew what was wrong they were just replacing the trim units and they eventually would fail too.

 

[seasick]

Interesting. I haven't heard about that issue. I did check that the assembly is the same part number for both models.

 

[HalcyonDays]

Legend thank you for the reply. "the engine would only tilt down to the top of the trim pistons". This is the exact problem that I am having, I will relay your post to my Grady White Yamaha dealer to see if they can find out more about "it is a known Yamaha issue and it is a relatively easy fix". Hopefully can be repaired for next boating season. Once the internal bolts were replaced did the problem reoccur?

 

[Legend]

Legend thank you for the reply. "the engine would only tilt down to the top of the trim pistons". This is the exact problem that I am having, I will relay your post to my Grady White Yamaha dealer to see if they can find out more about "it is a known Yamaha issue and it is a relatively easy fix". Hopefully can be repaired for next boating season. Once the internal bolts were replaced did the problem reoccur?

No issues since the repair

 

[Sardinia306Canyon]

I have the same 2019 F250 as your F300 and never had this problem

Have you tried to use also the tilt/trim switch on the cowling, not only the one on the control?
Can you hear them working if you press either switch?
Have you tried to loosen the manual release screw to see what happen then?

Noisy trim/tilt is usually either lack of oil or dry/not sufficient grease inside the pivoting system what blocks the outboard from trimming down. The lack of oil leads to not be able to raise the engine fully.

The internal bolt problems may be the culprit as those probably block oil flow to lower the trim rams so the outboard stay blocked there. And in your case with twins you may have a series with a fault.
Check your serial numbers if the last digits are near or the next number to see if they where manufactured in the same moment.

The grease on top of the Ram has nothing to do with not descending, its used to reduce friction between the ram's top and the point on the engine bracket where they touch and protect them from corrosion.

Chris

 

[Legend]

Legend thank you for the reply. "the engine would only tilt down to the top of the trim pistons". This is the exact problem that I am having, I will relay your post to my Grady White Yamaha dealer to see if they can find out more about "it is a known Yamaha issue and it is a relatively easy fix". Hopefully can be repaired for next boating season. Once the internal bolts were replaced did the problem reoccur?

How did you make out with the trim issue?

 

[HalcyonDays]

Spoke with my local Grady White dealer who is committed to looking into the issue with Yamaha. Will let me know what they find out in time for next boating season.

 

[gbgrady208]

I had the same issue on one of my new 2021 300's about three months after purchase. The dealer who does my maintenance bleed some air out of the system and now have over 400 hours on the engines without the issue reappearing. Air and/or low fluid can certainly cause this.

 

[Sardinia306Canyon]

Always when I had low oil and air in the trim/tilt system the engine would not raise but sink all down.

A stuck valve inside the tilt/trim mechanism including the pump could lead to not lowering as there must be a blockage if the trim pump motor is turning in both directions.

Chris

 

[HalcyonDays]

Problem resolved. There are two bolts that the lower piston/rams comes in contact with as the motor is being lowered. There should be a bevel on the contact head of these bolts that allows the rams to retract. The original bolts on this year motor had flat heads and the piston/ram would occasionally get caught and not allow the rams to retract causing the motor not to go down. Two new bolts and problem seems to be resolved.